Peter,
I believe I have now understood your concerns on equality ...
Would the following text near the beginning of the abstract syntax section
help (help enough to reduce it to a minor concern?)
[[
Note: Syntactic equality, between RDF graphs, URI references or literals,
is often inappropriate for applications. Semantic notions, defined in
[RDF-SEMANTICS], such as that of entailment between graphs, or that of
having the same denotation are usually preferable.
]]
Jeremy